The External_Media_Identifier message can be considered normal for now, as we currently do not have the package for it (it is not open source - though Pluto is supposed to provide us with a binary)

Regarding the window hanging - this seems to have shaped up in the last couple alpha updates due to Launch_Manager being back in the picture. Though TSCHAK and I had a conversation about this "last resort" window and I believe eventually we will probably eliminate its display except in last-case scenarios.